Systems which display images are used for many purposes. Sometimes the image is simply displayed and viewed directly, such as a cathode ray tube used as a television screen or computer display. A concern in viewing images from a cathode ray tube is the viewer's exposure to radiation from the screen of the device. Since the radiation is low-level radiation, exposure can be reduced by distancing a viewer from the screen.
In another instance, it is often desirable to project to a viewer an image which is spatially realistic. For example, projecting images of landscape scenery to trainees in a flight simulator. Systems which produce an infinity or near-infinity image are used for this purpose. In such systems, the viewed image has usually been reflected and otherwise manipulated in some way. A problem with these systems is that they are complex because they use several components to produce the image to the viewer. A typical system may consist of a projector and projection screen, mirrors, beamsplitters, lenses and a final image viewing screen. The complexity of such a system is further increased by the numerous mechanisms needed to support and align the components. The complexity increases the cost of a system, and the more complex the system the more costly. In addition to the expense related to the number of components, some of the individual components are inherently costly. For example, a quality projector and screen display is relatively expensive, particularly when compared to an image-originating device such as a cathode ray tube. In general, quality optical items are expensive. Also, with respect to projection systems, the projector normally used has a shorter useful life than a CRT. The complexity of some systems also causes image abnormalities such as under illumination, lack of definition, lack of clarity, distortion and chromatic aberrations. Further, alignment of an image in a projector system which uses red, blue and green tubes is difficult. All of the problems outlined above may be exacerbated when a mosaic image is attempted. A mosaic image is a composite image of distinct displays. A display system which eliminates some of the components mentioned above would be simpler to construct, more compact, less expensive and capable of more easily providing a clear, distortion-free image.